tdesktop/Telegram/SourceFiles/mtproto/auth_key.cpp

116 lines
3.9 KiB
C++

/*
This file is part of Telegram Desktop,
the official desktop version of Telegram messaging app, see https://telegram.org
Telegram Desktop is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
It is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
In addition, as a special exception, the copyright holders give permission
to link the code of portions of this program with the OpenSSL library.
Full license: https://github.com/telegramdesktop/tdesktop/blob/master/LICENSE
Copyright (c) 2014-2017 John Preston, https://desktop.telegram.org
*/
#include "mtproto/auth_key.h"
#include <openssl/aes.h>
namespace MTP {
void AuthKey::prepareAES_oldmtp(const MTPint128 &msgKey, MTPint256 &aesKey, MTPint256 &aesIV, bool send) const {
uint32 x = send ? 0 : 8;
uchar data_a[16 + 32], sha1_a[20];
memcpy(data_a, &msgKey, 16);
memcpy(data_a + 16, _key.data() + x, 32);
hashSha1(data_a, 16 + 32, sha1_a);
uchar data_b[16 + 16 + 16], sha1_b[20];
memcpy(data_b, _key.data() + 32 + x, 16);
memcpy(data_b + 16, &msgKey, 16);
memcpy(data_b + 32, _key.data() + 48 + x, 16);
hashSha1(data_b, 16 + 16 + 16, sha1_b);
uchar data_c[32 + 16], sha1_c[20];
memcpy(data_c, _key.data() + 64 + x, 32);
memcpy(data_c + 32, &msgKey, 16);
hashSha1(data_c, 32 + 16, sha1_c);
uchar data_d[16 + 32], sha1_d[20];
memcpy(data_d, &msgKey, 16);
memcpy(data_d + 16, _key.data() + 96 + x, 32);
hashSha1(data_d, 16 + 32, sha1_d);
auto key = reinterpret_cast<uchar*>(&aesKey);
auto iv = reinterpret_cast<uchar*>(&aesIV);
memcpy(key, sha1_a, 8);
memcpy(key + 8, sha1_b + 8, 12);
memcpy(key + 8 + 12, sha1_c + 4, 12);
memcpy(iv, sha1_a + 8, 12);
memcpy(iv + 12, sha1_b, 8);
memcpy(iv + 12 + 8, sha1_c + 16, 4);
memcpy(iv + 12 + 8 + 4, sha1_d, 8);
}
void AuthKey::prepareAES(const MTPint128 &msgKey, MTPint256 &aesKey, MTPint256 &aesIV, bool send) const {
uint32 x = send ? 0 : 8;
uchar data_a[16 + 36], sha256_a[32];
memcpy(data_a, &msgKey, 16);
memcpy(data_a + 16, _key.data() + x, 36);
hashSha256(data_a, 16 + 36, sha256_a);
uchar data_b[36 + 16], sha256_b[32];
memcpy(data_b, _key.data() + 40 + x, 36);
memcpy(data_b + 36, &msgKey, 16);
hashSha256(data_b, 36 + 16, sha256_b);
auto key = reinterpret_cast<uchar*>(&aesKey);
auto iv = reinterpret_cast<uchar*>(&aesIV);
memcpy(key, sha256_a, 8);
memcpy(key + 8, sha256_b + 8, 16);
memcpy(key + 8 + 16, sha256_a + 24, 8);
memcpy(iv, sha256_b, 8);
memcpy(iv + 8, sha256_a + 8, 16);
memcpy(iv + 8 + 16, sha256_b + 24, 8);
}
void aesIgeEncryptRaw(const void *src, void *dst, uint32 len, const void *key, const void *iv) {
uchar aes_key[32], aes_iv[32];
memcpy(aes_key, key, 32);
memcpy(aes_iv, iv, 32);
AES_KEY aes;
AES_set_encrypt_key(aes_key, 256, &aes);
AES_ige_encrypt(static_cast<const uchar*>(src), static_cast<uchar*>(dst), len, &aes, aes_iv, AES_ENCRYPT);
}
void aesIgeDecryptRaw(const void *src, void *dst, uint32 len, const void *key, const void *iv) {
uchar aes_key[32], aes_iv[32];
memcpy(aes_key, key, 32);
memcpy(aes_iv, iv, 32);
AES_KEY aes;
AES_set_decrypt_key(aes_key, 256, &aes);
AES_ige_encrypt(static_cast<const uchar*>(src), static_cast<uchar*>(dst), len, &aes, aes_iv, AES_DECRYPT);
}
void aesCtrEncrypt(void *data, uint32 len, const void *key, CTRState *state) {
AES_KEY aes;
AES_set_encrypt_key(static_cast<const uchar*>(key), 256, &aes);
static_assert(CTRState::IvecSize == AES_BLOCK_SIZE, "Wrong size of ctr ivec!");
static_assert(CTRState::EcountSize == AES_BLOCK_SIZE, "Wrong size of ctr ecount!");
AES_ctr128_encrypt(static_cast<const uchar*>(data), static_cast<uchar*>(data), len, &aes, state->ivec, state->ecount, &state->num);
}
} // namespace MTP